<xml>
<ToUserName><![CDATA[<{$toUsername}>]]></ToUserName>
<FromUserName><![CDATA[<{$fromUsername}>]]></FromUserName>
<CreateTime><{$time}></CreateTime>
<MsgType><![CDATA[text]]></MsgType>
<Content><![CDATA[<{$content}>]]></Content>
</xml>